The relief at the words 'outta my system' was probably a little too much for what it was, but Stiles was more afraid than he wanted to admit about the possibility of Sam, who seemed like a pretty capable guy with very little fear related to the supernatural (which was kind of a valuable trait in this town, all things considered), succumbing to alcohol.
"Look, I'm.. I'm sorry about your brother. I don't know what your world is like, but he seems like he was pretty tough." He sat up a little straighter. "I mean. He seems like he didn't go out without a fight, and--" He shrugged. "There was a guy here who knew if he went back it'd be to.. yeah, this isn't helping."
Stiles stood up and scratched the back of his neck, eyes narrowing and lips pressing together. "I know I'm not much more than an annoying kid who pretends he's got the answers, and we all know I don't, but if you ever want to talk it out or anything, I... well. I've lost some people. I've seen what the supernatural does to people and it's rough, so I--well, I get it, I guess."